Covering Apparatus

ABSTRACT

Apparatus for applying sheet material to framework elements comprises elongate support means for sheet material and means for attachment of said support means to framework elements, in which the elongate support means comprise a base member having upstanding stud members for engagement in use with pre-formed holes formed in the sheet material and a capping member for applying over said base member to apply out-of-plane tensioning deformation to said sheet material, in which the capping member includes groove formations for receiving the edge of sheet material formed as a keder.

This invention relates to covering apparatus and especially, but not exclusively, provides covering apparatus suitable for the erection of temporary roofing or containment structures of the type for providing a weatherproof membrane over large areas, particularly where long-span roof trusses are involved.

EP-A-0924364 describes a roofing structure assembly for attachment to scaffold members and comprising elongate roofing material support members and a flexible roofing material engagable with the elongate support members, in which the elongate support members include means for tensioning the roofing material between adjacent elongate support members in use. The elongate support members are provided with upstanding stud members over which the roofing material is located and by virtue of which the tensioning means are secured to the support members, clamping the roofing material between them. The roofing material is in strip or sheet form with pre-formed holes for receiving the stud members, edge regions of adjacent sheets of roofing material being arranged in overlapping relationship.

While the apparatus describes in EP-A-0924364 remains useful, it does have certain disadvantages. In particular, depending on the requirements or constraints of a particular job in hand, it may be necessary initially to erect the scaffold members and, thereafter, to apply the roofing material by use of a ladder or a scaffolding tower. In particular, when fitting end doors of the pram hood type to structures such as a temporary aircraft hangar, it would be necessary with the known equipment to use long ladders or mechanical access equipment to fit the lower edge of the top door sheet to the upper door arch frame. Furthermore, the existing apparatus permits the use of only one layer or membrane of roofing material, which is undesirable in locations where heat insulation is required.

It is an object of the present invention to provide covering apparatus which avoids the disadvantages of the apparatus as already known.

The present invention provides, in one aspect, apparatus for applying sheet material to framework elements, the apparatus comprising elongate support means for sheet material and means for attachment of said support means to framework elements, in which the elongate support means comprise a base member having upstanding stud members for engagement in use with pre-formed holes formed in the sheet material and a capping member for applying over said base member to apply out-of-plane tensioning deformation to said sheet material, in which the capping member includes groove formations for receiving the edge of sheet material formed as a keder.

In apparatus according to the present invention, the keder grooves formed in the capping members permit the use of keder-edged sheet material either as an alternative to the stud-engaged sheet material or additionally thereto.

Preferably, the base member comprises a longitudinal central zone from which the stud members extend, the central zone being bounded by longitudinal channel members. The capping member preferably also has a central zone for applying over the central zone of the base member, the central zone of the capping member being provided with holes for receiving the stud members, and downwardly-depending U formations which co-operate with the channel members of the base member to define a space for receiving and tensioning sheet material applied over the stud members. The advantage of providing channel members and co-operating U members is that the sheet material is subject to a double out-of-plane deformation, whereby the profile of the untensioned fabric is maintained in the tensioned fabric, thereby reducing creasing and the creation of resulting zones of weakness in sheet material panels where they are taken over an apex or eaves of a structure, or subject to other changes in pitch.

Advantageously, the central zone of the capping member is extended on each side over the U channels, the outer edge of the extensions defining a longitudinal gap with the outer or distal edge of the U member and, thereby, creating the keder groove.

Preferably, the upstanding stud members are screw-threaded to receive a clamping nut, to secure the capping and base members together with tensioning of fabric applied over the stud members. Preferably, the upstanding stud members comprise pins formed in a lower portion with a standard or fine screw thread for receiving a nut for tightening purposes again the base member and in an upper portion with a further screw thread for receiving a clamping nut for clamping the capping member to the base member and, thus, for applying tensioning force to the sheet material. Preferably, the clamping nut is formed from a plastics, for example nylon, material and the thread is relatively coarse. Advantageously, the stud members are formed, in a zone between the respective upper and lower screw-threaded portions, with a formation defining parallel flat edges for receipt in a longitudinal channel or groove formed in the base member, whereby a tightening nut may be applied to the lower screw-threaded portion and tightened against the base member, the stud being held captive in the base member by virtue of the flats engaging with the sides of the channel. Preferably, the formation defining the flats is formed as a hexagon. The longitudinal channel or groove formed in the base member may be shaped or dimensioned to accommodate a resilient, for example plastics or rubber, sealing material to avoid the use of adhesive sealant strips which tend to become detached in high ambient temperature environments.

The means for attachment of the support means to the framework elements preferably comprises a bracket having downwardly-depending legs for engaging astride the framework element in known manner and upper means for attachment to the support means. Preferably, the attachment bracket includes an upper cross-member formed with an aperture through which, in use and when attached to the support means, the lower portion of the upstanding stud member can protrude to ensure that the attachment bracket is held in registration with the stud member and to prevent relative longitudinal movement between the attachment bracket and stud member.

Conveniently, the upper cross member of the attachment bracket is formed with curved shoulders, the base member of the support means being fitted to and engaged with the attachment bracket by a pivoting movement from one side to the other across the curved shoulders. Thus, one shoulder may be formed with a lateral notch which receives a tongue formation formed on one side of the lower part of the base member, engagement of the tongue in the notch providing a fulcrum about which the base member can pivot until a further tongue formed on the other side of the lower part of the member engages against an abutment formed on the other shoulder of the attachment bracket. Preferably, the attachment bracket carries a laterally-disposed spring-loaded latch pin with a sloping front face whereby, on pivotal movement of the base member and as the further or second tongue moves in proximity to the abutment member, the second tongue engages with the sloping face of the latch pin and displaces it, against spring pressure, until it is free to return forwards to retain the second tongue, and hence the base member itself, in position on the attachment bracket. Preferably, the end of the latch pin is formed with an under-cut to define a flat face parallel with the axis of the pin and which is use engages against the upper surface of the second tongue. However, correct cooperation of the sloping front face of the pin with the second tongue requires that the pin is correctly angularly disposed within the attachment bracket and, in an alternative arrangement to avoid the need to ensure that the pin is in the correct angular orientation, a pair of pins may be provided, parallel and spaced apart and connected together at their ends remote from their front faces with a bridging or web portion, whereby the pins and web portion constitute a V-shaped pin member. The pins are journalled in corresponding parallel channels formed in the attachment bracket and the ends of the pins have co-planar sloping portions, whereby they are necessarily retained with the sloping portions at the correct disposition for cooperating with the second tongue of the base member. The bridging or web portion also makes it easier for the pins to be gripped for insertion and removal purposes.

Attachment brackets of the type described, suitable for use in connecting together a framework element and support means for sheet material, constitute a further aspect of the present invention.

The framework elements may be standard plain cylindrical tubes such as scaffolding poles or, alternatively, are or may comprise tubular poles having pre-formed through-holes to accommodate a snapper pin with a resilient wire retainer which passes through coaxial holes formed in the respective legs of the support bracket and through the holes pre-formed in the tubes, as more fully described in EP 0924364 A. If the framework elements comprise standard scaffolding poles, the legs of the support brackets may be formed with upturned lower ends which may be engaged with scaffold clamps, also as described in EP 0924364 A.

In use, successive support means may either be arranged co-axially or, alternatively, at a shallow angle by appropriate mitre-cutting of the end faces, whereby the channel members and keder grooves remain in registration. Keder-edged panels of sheet material may be fitted from one side only of the roof structure, thus avoiding the need for operatives to climb on the structure. Where the roof of a structure can be assembled at ground level and then jacked or lifted into position with a crane, punched sheets may be attached to the stud members and tensioned by means of the capping member, gaps between them being covered with a keder-edged panel. In such an arrangement, the edges of the panels engaged with the stud members will effectively form a gasket under the keder-edged panel to act as a seal over gaps between adjacent support means.

Using apparatus according to the invention, it is possible, according to the on-site requirements, to use either sheet material panels with preformed holes for engagement over the stud members and/or keder-edged panels. If keder-edged panels on their own are used, a narrow fabric strip to act as a sealing gasket is preferably fitted to the upper side of the base member.

When fitting doors of the pram hood type to an aircraft hangar construction, the use of keder panels allows the upper panels to be fitted from one side only and from ground level, the leading edge of the keder panel then being drawn through the keder grooves in adjacent support means, the grooves being in end-to-end registration with each other, by means of a rope or cable from the other side.

Optionally, apparatus according to the invention may include two capping members, the upper capping member being inverted over the lower capping member and, thus, providing for overlapping fabric panels, in the manner of overlapping roof tiles.

In order to provide improved insulation in the resulting structure, an inner wall may be formed from fabric material attached to the studs and tensioned by the capping member and the outer wall may be formed from keder-edged panels pulled along and accommodated in the keder grooves. Optionally, the space between the inner and outer walls may be inflated to enhance the insulating properties and to apply tension to the outer wall panels. For sealing purposes, the ends of the respective inner and outer wall panels may be passed over a tube or other support fitted at the eaves.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings, of which:

FIG. 1 is a fragmentary view of a scaffolding structure erected to form the frame work of a temporary building, with an enlarged inset view showing apparatus according to the present invention attached thereto;

FIG. 2 is perspective view showing an attachment bracket engaged with a base member comprising a fixing rail and a capping strip;

FIG. 3 is a perspective view of the attachment bracket of FIG. 2;

FIG. 4 is a front view of an attachment bracket attached to a scaffolding member with sheet materials engaged by the fixing rail and capping strips;

FIG. 5 is an underplan perspective view of the fixing rail and capping strip; and

FIG. 6 shows an alternative pin arrangement for attachment of the attachment bracket to the fixing rails.

With reference firstly to FIG. 1, the wall and roof frames of a temporary structural building are shown, formed from scaffolding members, attached to the outer elements of which is a fragmentary or short section of the component parts of apparatus according to the invention and consisting of fixing rail (attachment) brackets, a fixing rail and a capping strip, to which sheet material panels (not shown) are attached as hereinafter described.

With reference to FIG. 2, the assembly as shown consists of an attachment bracket, shown generally at 10, a fixing rail, shown generally at 11, and a capping strip, shown generally at 12. The fixing rail is supported on the upper member of the attachment bracket and the capping strip is supported on the fixing rail in a manner hereinafter described in more detail.

The attachment bracket 10 is formed with downwardly-depending legs 13, 14 for engagement, in use, about a main structural element such as a scaffolding pole (not shown in FIG. 2). The legs are provided with coaxial through-holes 15, 16. The upper end of the attachment bracket 10 is provided with a cross-member 17 bounded by curved shoulders 18, 19, the lower part of shoulder 19 being provided with a notch 20 and the lower part of shoulder 18 being provided with an externally extending lug 21 defining an upper-facing abutment surface. A pin 22 is slidingly journalled across the support bracket from a position below the notch 20 to above the lug 21; the pin is biassed towards the side of the bracket including the lug 21 by virtue of a helical spring 23. The pin has a sloping front face 24, as shown more clearly in FIG. 3, and is undercut at its outer end region 25 to define, together with the lug 21, a gap for receiving, as will be described, a tongue formed as part of the fixing rail 11. The pin 22, again as more clearly shown in FIG. 3, is preferably offset to one side of the support bracket and, in the upper cross member 17, there is formed a central hole 26 with a countersink 27.

The fixing rail 11 is formed with a central box section defined by lower and upper walls 28, 29 and inwardly-sloping side walls 30, 31. The lower wall 28 is extended outwardly on each side by arms 32, 33 defining, together with respective side walls 30, 31, longitudinal channels. Downwardly- and inwardly-facing longitudinal tongues 34, 35 extend from the lower part of each arm 32, 33. The fixing rail is located on and engaged with the attachment bracket 10 by, firstly, engaging tongue 35 in notch 20 and, thereafter, pivoting the fixing rail about a fulcrum constituted by the edge face of the tongue 35 against the blind end of the notch 20 until the opposite tongue, 34, rests on the abutment surface of lug 21. In the course of the pivotal movement, the edge face of tongue 34 will engage the sloping surface 24 of pin 22 and force it to retract, against the biassing pressure of spring 23, until the tongue 34 moves clear of the face 24, whereupon the pin 22 will return under pressure of the spring 23 to retain the tongue 34 in the gap between the lug 21 and undercut end region of the pin 22.

The upper wall 29 of the central box section of the fixing rail 11 is formed as a longitudinal groove 36 with inwardly-sloping end walls 37, 38. A stud member 39, see in particular FIG. 4, is formed with an upper, coarse screw-threaded section 40, a lower, fine screw-threaded section 41 and intermediate hexagon 42. The hexagon is held captive in the groove 36, and is secured in place by nut 43 journalled on the lower screw-threaded portion 41 of the stud member. The lower part 41 of the stud member passes through hole 51 formed in lower wall 28 of the central box section (see FIG. 5) and through hole 26 formed in the upper cross member 17 of the attachment bracket 10, the hole 26 having a sufficiently large diameter to accommodate the lower end of the stud member 39 as the fixing rail is rotated into position about the end face of the tongue, as described hereinabove. The clearance provided by the hole 51 allows use of a socket spanner to tighten nut 43. Preferably, a resilient plastics or rubber sealing or gasket strip is accommodated in the groove 36 and retained therein by the inwardly-sloping walls 37, 38 to clamp or seal the fabric sheets or panels between the fixing rail and capping strip.

The capping strip 12 consists essentially of a flat central bridging part 44 with side U formations 45, 46 which, together with lateral extensions of the bridging part 44, define keder channel access grooves 49, 50. The central bridging part of the capping strip 11 is formed with holes—which enable the capping strip to be applied over the upstanding stud members 39 and tightened down on the fixing rail by a nut (not shown) carried on screw threads 40.

FIG. 5 shows, in more detail, the lower end 41 of stud member 39 and nut 43, accommodated with clearance in hole 51 formed in the lower wall 28 of fixing rail 11.

In use and with reference to FIG. 4, the support bracket 10 is attached to scaffolding pole 52 by pin 53 which passes through the coaxial holes 15, 16 formed in the legs of the support brackets and through corresponding holes formed in the tubular wall of the scaffolding member 52. The pin is secured in known manner, for example by a resilient wire retainer (not shown). Respective roofing panels 54, 55 have holes pre-formed along edge regions 56, 57, inwardly of the edges, the holes being formed at the same spacing as that between adjacent stud members 39 as attached to the fixing rail 11. Further roofing panels 58, 59, formed with keders 60, 61 along their edges, are accommodated in and extend through keder grooves 49, 50 formed at each side of the central or bridging part of capping strip 12. With the capping strip 12 tightened down on fixing rail 11, the fabric panels 54, 55 are subject to two-way out-of-plane deformation and are thus subject to tension.

As can be understood, attachment brackets may readily be fitted to scaffolding poles before erection of the structural frame work of the building and the fixing rail is easily attached to the attachment brackets by virtue of the rotational attachment mechanism involving the use of the spring-loaded latch pin 22. In a typical arrangement, fixing rails are supplied in lengths of 3 m and have six stud members at intervals of 500 mm, attachment brackets being provided for alternate stud members and thus at intervals of 1 metre.

FIG. 6 shows an exploded perspective view of an alternative attachment bracket/pin assembly. The attachment bracket 62 is similar to the bracket 10 as previously described but is formed with a pair of parallel journals 63 through the upper parts of the walls for sliding receipt of the pins 64 of a V-shaped plunger 65. The pins have co-planar sloping end face portions 66. Helical springs 67 are carried by the pins 64 between the walls of the bracket, the free ends of the springs abutting against circlips 68 held in grooves 69 so that, on retraction of the pins by sliding contact of the sloping end portions 66 against the tongue of a fixing rail, as described with reference to FIGS. 2 and 3, the springs are compressed to exert return pressure on the pins. 

1. Apparatus for applying sheet material to framework elements, the apparatus comprising elongate support means for sheet material and means for attachment of said support means to framework elements, in which the elongate support means comprise a base member having upstanding stud members for engagement in use with pre-formed holes formed in the sheet material and a capping member for applying over said base member to apply out-of-plane tensioning deformation to said sheet material, in which the capping member includes groove formations for receiving the edge of sheet material formed as a keder.
 2. Apparatus according to claim 1, in which the base member comprises a longitudinal central zone from which the stud members extend, the central zone being bounded by longitudinal channel members for receiving, in use, out-of-plane deformed portions of sheet material.
 3. Apparatus according to claim 2, in which the capping member has a central zone for applying over the central zone of the base member, the central zone of the capping member being provided with holes for receiving the stud members, and downwardly-depending U formations externally of the central zone which co-operate with the channel members of the base member to define a space for receiving and tensioning sheet material applied over the stud members.
 4. Apparatus according to claim 3, in which the central zone of the capping member includes extensions on each side over the U channels, the outer edge of the extensions defining a longitudinal gap with the outer or distal edge of the U member and, thereby, creating the keder groove.
 5. Apparatus according to claim 1, in which the upstanding stud members are screw-threaded to receive a clamping nut, to secure the capping and base members together with tensioning of fabric applied over the stud members.
 6. Apparatus according to claim 5, in which the upstanding stud members comprise pins formed in a lower portion with a standard or fine screw thread for receiving a nut for tightening purposes against the base member and in an upper portion with a further screw thread for receiving a clamping nut for clamping the capping member to the base member and, thus, for applying tensioning force to the sheet material.
 7. Apparatus according to claim 1, in which the means for attachment of the support means to the framework elements comprises a bracket having downwardly-depending legs for engaging astride the framework element and upper means for attachment to the support means.
 8. Apparatus according to claim 7, in which the attachment bracket includes an upper cross-member formed with an aperture through which, in use and when attached to the support means, the lower portion of the upstanding stud member can protrude.
 9. Apparatus according to claim 7, in which the upper cross member of the attachment bracket is formed with curved shoulders.
 10. Apparatus according to claim 9, in which one shoulder is formed with a lateral notch which receives a tongue formation formed on one side of the lower part of the base member and the other shoulder is formed with an abutment against which a further tongue formed on the other side of the lower part of the base member engages.
 11. Apparatus according to claim 7, in which the attachment bracket carries a laterally-disposed spring-loaded latch pin to secure the bracket in engagement with the support means.
 12. Apparatus according to claim 11, in which the latch pin is one of a pair of pins, arranged in parallel relationship and spaced apart, connected together at their ends remote from their front faces with a bridging or web portion, whereby the pins and web portion constitute a V-shaped double-pin member.
 13. Apparatus according to claim 1 and including two capping members, the upper capping member being inverted over the lower capping member.
 14. A structure comprising apparatus according to claim 1 and sheet material supported thereby, in which adjacent support means are arranged co-axially or at a shallow angle by mitre-cutting of the end faces, whereby the channel members and keder grooves remain in registration.
 15. A method of construction of a temporary roofing or containment structure, the method comprising assembling two or more sets of apparatus according to claim 1 with the channel members and keder grooves of adjacent sets in registration and fitting keder-edged panels of sheet material from one side of the structure.
 16. A method according to claim 15, in which the structure includes a roof which is assembled at ground level and lifted or hoisted into position punched sheets being attached to the stud members and tensioned by means of the capping member, gaps between them being covered with a keder-edged panel.
 17. A method according to claim 15, in which, in order to provide improved insulation, an inner wall is formed from fabric material attached to the studs and tensioned by a capping member and the outer wall is formed from keder-edged panels pulled along and accommodated in the keder grooves, the space between the inner and outer walls being capable of inflation to enhance the insulating properties and to apply tension to the outer wall Panels.
 18. An attachment bracket for connecting together a framework element and support means for sheet material as defined in claim 1, the bracket comprising legs for engaging astride the framework element and upper means for attachment to the support means, the bracket including an upper cross-member formed. with an aperture and curved shoulders, one shoulder being formed with a lateral notch and the other shoulder including an abutment, the attachment bracket carrying at least one laterally-disposed spring-loaded, latch pin, the support means being retained on the bracket by engagement of the latch pin or pins with the support means. 